Saved Search Criteria Most Recent Date

Hi,

I am trying to build a KPI that calculates the total value of product on hand for a given vendor. To do this I thought I would do an item saved search. I was thinking pull all items that exist on a purchase order for the given vendor. From there I can grab on hand quantity and rate to get a total value. However, in order to get the most accurate rate, I only want the most recent purchase order to show up in my results. Currently, my results show all the purchase orders.